This invention relates to an absorbent article in which superabsorbent material is contained in pockets of another, non-absorbent layer. The invention eliminates the need for a separate absorbent layer, and reduces the total number of layers required in the article.
Absorbent composites suitable for use in disposable absorbent garments such as diapers, adult incontinent products, and the like, are known. Such absorbent composites are described, for example, in U.S. Pat. No. 4,699,619 issued Oct. 13, 1987 to Bernardin, U.S. Pat. No. 4,798,603 issued Jan. 17, 1989 to Meyer et al., U.S. Pat. No. 4,834,735 issued May 30, 1989 to Alemany et al., U.S. Pat. No. 5,147,343 issued Sep. 15, 1992 to Kellenberger, and U.S. Pat. No. 5,149,335 issued Sep. 22, 1992, to Kellenberger et al.
Generally, such absorbent composites comprise a matrix for containing a high-absorbency material in another absorbent material. Suitable matrices for containing the high-absorbency material include absorbent fibrous matrixes, such as those formed from air-laid cellulosic fibers or a coform material comprising cellulosic fibers and meltblown polyolefin fibers. A wide variety of high absorbency materials (also known as superabsorbent materials) are known to those skilled in the art. See, for example, U.S. Pat. No. 4,076,663 issued Feb. 28, 1978 to Masuda et al, U.S. Pat. No. 4,286,082 issued Aug. 25, 1981 to Tsubakimoto et al., U.S. Pat. No. 4,062,817 issued Dec. 13, 1977 to Westerman, and U.S. Pat. No. 4,340,706 issued Jul. 20, 1982 to Obayashi et al.
Many known absorbent composites comprising a high-absorbency material employ the high-absorbency material in relatively low concentrations. That is, many of the absorbent composites comprise air-laid cellulosic fibers and less than about 20 weight percent of high-absorbency material. This is due to several factors.
Many high-absorbency materials are unable to absorb a liquid at the rate at which the liquid is applied to the absorbent composites during use. Accordingly, a relatively high concentration of fibrous material is desirable to temporarily hold the liquid until the high-absorbency material can absorb it. Further, the fibers serve to separate the particles of high-absorbency material so that gel-blocking does not occur. Gel-blocking refers to the situation wherein particles of high-absorbency material deform during swelling and block the interstitial spaces between the particles, or between the particles and fibers, thus preventing the flow of liquid through the interstitial spaces.
The presence of a relatively low concentration of high-absorbency material and a relatively greater concentration of fibrous materials has resulted in the production of absorbent composites which tend to be relatively thick. In some instances, the use of a relatively thick absorbent composite in a disposable absorbent garment is acceptable. However, in recent years it has become increasingly desirable to produce absorbent composites which are thin compared to the more traditional absorbent composites but which still possess the same absorbent capacity. The desire to produce relatively thin absorbent composites has resulted in the desire to incorporate ever-increasing amounts of high-absorbency material into the absorbent composites. This is because the absorbent capacity of such high-absorbency materials is generally many times greater than the absorbent capacity of fibrous materials. For example, a fibrous matrix of wood pulp fluff can absorb about 7-9 grams of a liquid, (such as 0.9 weight percent saline) per gram of wood pulp fluff, while the high-absorbency materials can absorb at least about 15, preferably at least about 20, and often at least about 25 grams of liquid, such as 0.9 weight percent saline, per gram of the high-absorbency material.
U.S. Pat. No. 5,601,542, issued to Melius et al., discloses an absorbent article in which superabsorbent material is contained in layers of discrete pouches. The pouches are adjacent one another, and are formed in one or more substrate layers. The patent illustrates a diaper which includes a substantially liquid impermeable outer cover, a liquid permeable body-side liner, and an absorbent composite between the outer cover and body-side liner. A surge management layer, positioned adjacent to the body-side liner in the crotch region of the latter, regulates the flow of liquid surging into the absorbent composite. The surge management. layer may be above (on the outside of) the body-side liner, or may be between the body-side liner and the absorbent composite.
There is a need or desire in the industry to provide diapers and other absorbent articles having fewer layers, lighter construction, and lower production costs, without losing any of the functions provided by the conventional layers.
The present invention is an absorbent article, such as a diaper, in which the functions of plural layers are combined into a single layer, thereby reducing the total number of layers without yielding any functions. Specifically, the present invention is directed to an absorbent article, such as a diaper, in which the absorbent function is integrated into either the surge material or the outer cover material, thus eliminating the need for a separate central absorbent composite. The objective of the invention is accomplished by forming a plurality of small pockets in the surge material and/or the outer cover material. A superabsorbent material is added to the pockets, causing the surge layer and/or the outer cover to perform an absorbent function.
More specifically, the present invention is directed to an absorbent article including a liquid-permeable body-side liner, a surge layer adjacent to the body-side liner, and a substantially liquid-impermeable outer cover adjacent to the surge layer. At least one of the surge layer and the outer cover includes a plurality of pockets, and a quantity of superabsorbent material within the pockets. Put another way, the pockets containing the superabsorbent can be in the surge layer, in the outer cover, or in both the surge layer and the outer cover material, thus eliminating the need for a separate absorbent composite layer between the surge layer and the outer cover material.
With the foregoing in mind, it is a feature and advantage of the invention to provide an absorbent article having three essential layers, namely a body-side liner, a surge layer, and an outer cover, wherein at least one of the surge layer and outer cover contains a superabsorbent material.
It is also a feature and advantage of the invention to provide an absorbent article having lower cost, simpler construction and lighter weight than conventional absorbent articles.
It is also a feature and advantage of the invention to provide an absorbent article having less bulk than conventional absorbent articles.
It is also a feature and advantage of the invention to provide a highly water vapor breathable absorbent garment, promoting skin wellness.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments. This detailed description is exemplary, and should be construed as illustrating rather than limiting the invention.